From Urban Oil Pollution In Soil Screening Flooding Identification Of Bacteria And Their Physical And Chemical Properties

Microbial enhanced oil recovery (MEOR) is a technique to utilze microorganisms and their metabolic products to improve the recovery of crude oil from reservoir rocks. MEOR was the technology that poured microorganism and microbial metabolic products into crude oil in order to improve crude oil recovery ratio by some microbial actions or some characters of microbial metabolic products acted to crude oil and then using these actions or characters could change physical and chemical specialities of the crude oil.Bacteria are the only microorganisms which have been proposed for enhanced oil recovery process. They are small in size, grow exponentially and tolerate dicky environments such as : high temperature ,high water salinity and high pressure.They can enhance oil recovery by producing metabolic compounds such as gases,acids, surfactants and polymers. The strains which could produce acid, gas or surfactant were sifted from extended pollutional water and soil,and their physical ,chemical properties and 16S rDNA sequence were analyzed synchronously in our test in order to identify these bacteria,understand and master the physiological and biochemical characteristics of strains.A theoretical foundation about how to train and screen oil bacterial strain could be formed. By measuring pH, surface tension, viscosity of crude oil and other indicators of crude oil emulsion formed in the process of strains and crude oil in the laboratory,we establish the single well basis in field test for the application of microbial stimulation.The main contents are as follows:Firstly, the development of MEOR as well as the research status in domestic and abroad were discussed, and the advantages of MEOR and the existing problems in the current and future development of MEOR technologies launched preconceptions were summarized. On this basis,This experiment lists the innovation points in this paper,and illustrate the research significance of this article clearly.Secondly, the separation of the oil displacement strains are screened. The oil was got as the only carbon source facultative celebrates the growth of bacterial strains 20 strains of oxygen, which come from daqing oilfield liquid, school corrupt oil pool, dining room oil pollution of soil and water, through the screen and purification at the beginning, the comprehensive growth ability to observe.Through analyzing the strains on the wave bottle drop oil, we screen four strains of bacteria namedⅠⅡ, A1 and A2, which could degrade oil well.Thirdly, These four oil strains above are identified. Programming a series of physiological and biochemical tests on the four strains screened out as to ensure they can produce acid, gas and biological surfactant which could extract oil more efficiently, Combined complicated physicochemical properties of trial with biochemical reaction experiment and 16S rDNA results, the strains are identified preliminarily as 2 kinds Bacillus subtilis, Pseudomonas aeruginosa and Bacillus cereus.Finally, the growth of 4 strains and the ability to degrade oil and decrease viscosity are further studied .According to the characteristics of target strains, the growth and the degradation of sticky oil were studied preliminarily.The result showed four strains have better ability to degrade oil and reduce oil viscosity.